Class: JsonTools::Patch

Inherits:
Object
  • Object
show all
Defined in:
lib/jsontools/jsontools.rb

Defined Under Namespace

Classes: FailedOperationError, InvalidPatchDocumentError

Constant Summary collapse

PATCH_OPERATIONS = 
{}

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(ops, with_predicates = false) ⇒ Patch

Returns a new instance of Patch.



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# File 'lib/jsontools/jsontools.rb', line 138

def initialize ops, with_predicates=false
  # Parse JSON if necessary
  if ops.is_a?(String) || ops.respond_to?(:read)
    ops = JSON.load(ops)
  end
  fail unless Array === ops
  @ops = ops
  # Should we include the JSON Predicate operations?
  # Off by default
  extend Predicate if with_predicates
rescue
  raise InvalidPatchDocumentError
end

Class Method Details

.add(params, target) ⇒ Object 



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# File 'lib/jsontools/jsontools.rb', line 181

def add params, target
  ptr = Pointer.new params['path']
  obj = ptr[target]
  fail if not (Array === obj || Hash === obj)
  if (Array === obj && ptr.last == '-') 
    obj.insert -1,params['value']
  else
    obj.insert JsonTools.fix_key(obj,ptr.last),params['value']
  end
rescue
   raise FailedOperationError
end

.copy(params, target) ⇒ Object 



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# File 'lib/jsontools/jsontools.rb', line 207

def copy params, target
  move_or_copy params, target, false
end

.move(params, target) ⇒ Object 



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# File 'lib/jsontools/jsontools.rb', line 203

def move params, target
  move_or_copy params, target, true
end

.move_or_copy(params, target, move = false) ⇒ Object 



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# File 'lib/jsontools/jsontools.rb', line 211

def move_or_copy params, target, move=false 
  from = Pointer.new params['from']
  to = Pointer.new params['path']
  fail if !from.exists?(target) #|| to.exists?(target)
  obj = from[target]
  val = obj[JsonTools.fix_key(obj,from.last)]
  remove(({'path'=>params['path']}), target) if move # we only remove it if we're doing a move operation
  add ({'path'=>params['to'],'value'=>val}), target
rescue
  raise FailedOperationError
end

.new_with_predicates(ops) ⇒ Object

Initialize a new Patch object with JSON Predicate Operations enabled



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# File 'lib/jsontools/jsontools.rb', line 154

def self.new_with_predicates ops
  new ops, true
end

.remove(params, target) ⇒ Object 



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# File 'lib/jsontools/jsontools.rb', line 194

def remove params, target
  ptr = Pointer.new params['path']
  return if not ptr.exists? target #it's gone, just ignore.. TODO: might still need to throw an error, but we'll skip it for now
  obj  = ptr[target]
  obj.delete_at JsonTools.fix_key(obj,ptr.last)
rescue
  raise FailedOperationError
end

.replace(params, target) ⇒ Object 



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# File 'lib/jsontools/jsontools.rb', line 223

def replace params, target
  ptr = Pointer.new params['path']
  fail if not ptr.exists? target
  obj = ptr[target]
  obj[JsonTools.fix_key(obj,ptr.last)] = params['value']
rescue
  raise FailedOperationError
end

.test(params, target) ⇒ Object 



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# File 'lib/jsontools/jsontools.rb', line 232

def test params, target
  ptr = Pointer.new(params['path'])
  fail if not ptr.exists? target
  obj = ptr[target]
  val = obj[JsonTools.fix_key(obj,ptr.last)]
  fail unless val == params['value']
rescue
  raise FailedOperationError
end

Instance Method Details

#apply_to(target) ⇒ Object

Apply the patch to a copy of the given target hash. The new, modified hash will be returned.



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# File 'lib/jsontools/jsontools.rb', line 172

def apply_to target
  apply_to! target.json_deep_copy
end

#apply_to!(target) ⇒ Object

Apply the patch to the given target hash object. Note that the target will be modified in place and changes will not be reversable in the case of failure.



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# File 'lib/jsontools/jsontools.rb', line 162

def apply_to! target
  @ops.each_with_object(target) do |operation, target|
    op = operation['op'].to_sym if operation.key?('op')
    PATCH_OPERATIONS[op][operation, target] rescue raise 'Invalid Operation'
  end
end

#register_op(sym, op) ⇒ Object 



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# File 'lib/jsontools/jsontools.rb', line 249

def register_op sym, op
  PATCH_OPERATIONS[sym] = op
end